The present invention concerns a novel system for transmitting data, using a multiplexing technique with an optical fiber.
In U.S. Pat. Nos. 3,215,135 and 3,249,105, optical blood pressure catheters are disclosed in which light is transmitted through optical fibers and a pressure-sensitive diaphragm varies the quantity of the light in response to the pressure exerted on the diaphragm. It is desirable to have the ability to sense a number of different pressure parameters using a single catheter. However, in view of the fact that a catheter should have a small diameter, it is advantageous to avoid having a number of optical fibers passing through a single catheter.
I have discovered a novel system and process by which a single optical fiber can be utilized within a catheter, for transmitting a plurality of informational items through the single optical fiber. The optical fiber being divided into a plurality of segments positioned end-to-end. In this manner, a critical care monitoring catheter could be provided in which a physician could monitor, simultaneously, mean right atrial pressure, right ventricular pressure, and pulmonary arterial or wedge pressure. Alternatively, utilizing the system of the present invention, a cardiac catharization catheter could be provided which would give simultaneous pressure measurements across any one or a combination of the valves of the heart. For example, the catheter could monitor the pressure across the aortic valve which measures the pressure gradient between the aorta and the left ventricle. Another example for which the present invention is useful is in connection with simultaneously measuring the pressures on opposite sides of a balloon in an angiographic catheter.
By utilizing an optical fiber to transmit the plurality of information simultaneously, rather than using electrical wiring, the patient is isolated from electric charges. It is to be understood, however, that although the illustrative embodiment of the invention is directed to a multi-information catheter, the system and process of the present invention are applicable to many other environments in which the transmission of data is required.
It is, therefore, an object of the present invention to provide a system for transmitting a plurality of informational items utilizing a single optical fiber.
Another object of the present invention is to provide a wavelength division multiplexing system utilizing an optical fiber, which system is relatively simple in construction and efficient in operation.
A further object of the present invention is to provide an optical pressure catheter that is operable to sense more than one item at a time using a single optical fiber.
Other objects and advantages of the present invention will become apparent as the description proceeds.